killing thousands of al qaeda and taliban, but more than 300 civilians, as well. a world away, in remote villages, you can hear them. like a distance, muted chain saw. a dull, but deadly roar. villagers describing it this way. "the drones are all over my brain. i can't sleep. when they're hovering over us, we're all scared." a reality we seldom see, says stanley mcchrystal, the retired general who once ran the military's drone strike program. >> if we are too casual about it, then we will forget how much scar tissue we build up in those countries. >> reporter: the general believes that americans should have the opportunity to know more about these secret drone wars, to weigh those benefits and risks. that rare opportunity will occur tomorrow, when john brennan speaks, diane. >> it is going to be a very combustive day. thank you, martha raddatz. >>> and also today, a more trusted part of american life has succumbed to modern times. the postal service announced today that saturday delivery of letters will soon end in august. only packages will come to your door. and